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Electric Power vs Gas Power...
Comparison of Electric Mopeds/Bikes and Gas Mopeds/Scooters
1 hp = 746 watts
XM-5000 at 5000 watts: 5000/746 = 6.7 hp has a top speed of 60 mph.
XM-3150 at 3100 watts: 3100/746 = 4.2 hp
EW-600 at 600 watts: 600/746 = 0.8 hp
EW-1500 at 300 watts: 300/746 = 0.4 hp
Chinese 300 cc about 13.0 hp = 9700 watts
Chinese 200 cc about 8.6 hp = 6415 watts
California 150 cc about 8.0 hp = 5968 watts has a top speed of 55 mph.
Chinese 25 cc about 5.375 hp = 4000 watts
Chinese 50 cc about 2.2 hp = 1641 watts.
Note that the Electric XM-5000 (compared to the California gas 150cc) has 1000 lower wattage and 1.3 lower horsepower but a higher top speed. Electric brushless rear hub motors have higher torque and higher efficiency. So comparable electric mopeds are faster and accelerate at a way higher rate.
Lead Acid (LA) or Lithium (Li)?
If an electric vehicle has 4, 5 or 6 batteries then it is a lead acid (LA) battery system. LA batteries are 12v: 4 batteries is 48 volts. Lithium systems will be 16 - 3v batteries (48 v), 20 - 3v batteries (60 v) or 24 - 3v batteries (72 v). Battery capacity is in Ah (amp hours). To compare amp hours: Lead acid will be 28, 36 or 48 Ah. Lithium will be 40 or 60 Ah.
Power Analysis?
Some companies misrepresent power. They quote a 5000 watt motor in the specs but does the system deliver 5000 watts to the motor? If the specs say 60 amps and 60 volts, there is 3600 watt input to the controller. Motors are at most only 85% efficient. So 3600 X .85 = 2880 watts delivered to the motor max! It does not matter that the motor has a 5000 watt capacity if it is only getting 2880 watts.
Chinese bikes are 55 or 60 amps to increase the range. A few bikes have 80 amps. This would be 60v X 80 amps X .85 = 4080 watts delivered. If customers want more range and higher speed while giving up power and acceleration, the designer will lower the amps. A 60 volt bike with 80 amps will be 33% better on acceleration and hill climbing. Use the ratio amps:volts (80/60 = 1.33) to compare systems.
Motor Comparison?
The torque of the motor is related to the diameter of the motor. The larger the motor diameter, the more torque. A 10.66 inch electric motor will have 33% more torque than an 8 inch diameter motor with the same amps and volts. The smaller the diameter of the motor, the faster it will run on the same volts. An 8 inch motor will have 33% more rpm than a 10.66 inch motor with the same amps and volts. But it will also take 33% more amps to have the same torque or hill climbing ability. The smaller the diameter of a motor the more it overheats. It has less mass to absorb the heat and less surface area to get rid of the heat.
Peak Voltage vs Nominal Voltage?
Battery systems have more voltage when newly charged then the system is rated for (nominal). A 60 volt rated bike system really has 72 volts peak. The voltage used for the calculation is peak volts:
5 lead acid (LA) batteries with 46 Ah at 60 volts nominal (72 volts peak) is a 72 x 46 Ah = 3.312 kwh system.
24 lithium batteries (Li) with 40 Ah each at 84 volts peak (72 volts nominal) is 84 x 40 Ah = 3.360 kwh.
24 lithium batteries (Li) with 60 Ah each at 84 volts peak (72 volts nominal) is 84 x 60 Ah = 5.040 kwh.
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